Wolfgang becker



/ W. BECKER.

"GUIDE P IN TOR PIANO KEYS. No. 366,615; Patent ed'luly 12, 1887'.

(No Model.)

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"WOLFGANG BECKER, OF CHICAGO, ILLINOIS.

GUIDE-PIN FOR PIANO-KEYS.

EIPECIFICATION forming part of Letters Patent No. 366,615, dated July12, 1887.

Application filed February :3, 1884. Serial No. IQLCG'I. (No model Toall whom it may concern:

Be it known that I, \VOLFGANGBEoKEma citizen of the United States,residing at Uhicago, in the county of Cook and State of lllinois, haveinvented a new and useful Improve mentin Pianos,of which thefollowingisaspeei fication.

This invention relates to the construction of the guide-pins employedwith piano-keys at their front ends to regulate their movement whenstruck; and it consists in the novel features hereinafter set forth.

In the accompanying drawings, Figure l is a central vertical sectionofakey and key-slip, showing my invention; and Figs. 2, 3, and 4are planviews of the guide-pin, showing different forms of the collar whichmaybe employed.

In said drawings, A represents the pianokey, 13 the key-rail, and B theslip. D is the guide-pin. The pin D consists of the upper guiding part,(I, (which is oval in cross section) andthe under screw-threadedportion, (1. The former extends up into the recess a in the key, and thelatter is inserted in the opening b in the key rail and slip. The pitchof the thread employed upon the stem should be fine,so thata halfturn ofthe pin will change its vertical position but very slightly, and Irecommend that the stem be sufliciently long to insure sufficientfriction against rotation. When thus constructed, it may be turnedso asto cause the guiding part to bind against the sides of the reeessesinthe keys,and anyloosening of the pin in its socket caused by suchadjustment will have no ill effect.

, The collar d, surrounding the pin at the junction of the guide andthreaded portions, is intended to support the soft washer (1, usuallyemployed heretofore to cushion the contact between the key and thekeyrail. Only a single thickness of washer is ever required with thisadjustable support,and thus thekey meets with afirm resistance when thelimit of its dip has been reached. If the pitch of the screw is fine,the halfturn of the pin,which may be the mi nimum rotation allowed, willnotbe found objectionable.

Thepin may be turned in the adjustment either by providing the collar,as shown, with slots in its periphery, into which a convenient tool maybe inserted, or by making the periphery angular, as also shown, so thata wrench may be applied, or with holesinto which hooks may be passed; orthe sockets of the pins may be extended to the bottom of the slip orinstrument, and a screw-driver be passed up from below, the end of thescrew being nicked to receiveit. This latter construction is illustratedin Fig. 1.

- I claim- 1. The combination of a vertically-adjustable guide-pinadapted to receive a rotating tool, as set forth,and consisting ofanoval head, a threaded stem,andcushion-s11pporting collar, and saidcushion, with the piano-key and rail, substantially as specified.

2. As a new manufacture, the adjustable guide-pin for regulatingpiano-keys having a guide portion, a threaded stem, and a collar between the guide portion and stem, said collar being adapted, as setforth, to receive an implement for rotating the pin,substantially asspecilied.

WOLFGANG BECKER.

Witnesses:

H. M. llIUNDAY, Enw. S. EVARTS.

